Waves LinMB Linear Phase MultiBand Software Audio Processor User guide

Type
User guide
Waves LinMB software guide page 1 of 28
Waves – Linear-Phase MultiBand
Software Audio Processor
Users Guide
version 2 Dec. 27th
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Chapter 1 – Introduction
Introducing Waves Linear-Phase MultiBand Processor.
The LinMB is an evolved version of the C4 MultiBand Parametric Processor. If
you are familiar with C4 you will find the Linear Phase MultiBand very similar,
adding some true breakthrough innovation and technology that yields superior
and purer results.
The LinMB has -
5 discrete bands each with its own gain and dynamics for equalizing,
compressing, expanding or limiting each band separately.
Linear Phase crossovers allow true transparency when the split is active
but idle. The only effect is pure delay with no coloration of any sort.
LinMB is equipped with the options for Automatic Makeup and gain Trim.
Adaptive threshold behavior achieves most effective and transparent
multiband dynamics processing.
LinMB has the visual interface of the award winning C4 with Waves’
unique DynamicLine™ display showing the actual gain change as an EQ
graph display.
Waves created the LinMB to answer to the most demanding and critical
requirements when Mastering any sound and genre of music.
While the Waves Masters bundle is focused to provide purist quality tools for
Mastering, there are many applications in which it may be very useful i.e.
Vocal processing, Transmission processing, Noise reduction, Track Strip.
The LinMB has a fixed amount of delay or fixed latency of about 70ms (3072
samples in 44.1-48kHz). Due to the intensive calculations required for the
Linear Phase crossover it is quite an achievement to have this work in real-
time in both TDM and Native. Much effort was put to optimize the
performance for specific CPU’s using Co processors such as Altivec on MAC
and SIMD on x86 type processors. Processing higher sample rate such as
96kHz will definitely require much more CPU then 48kHz.
MULTIBAND DYNAMICS
In MultiBand Dynamics processing we split the wide-band signal to discrete
bands. Each band is sent to its dedicated dynamics processor to apply the
desired dynamic gain adjustment or static gain. Splitting the signal has
several major consequences as follows:
Eliminates Inter Modulations between bands.
Eliminates gain riding between different frequency bands.
Allows setting each band’s attack, release times scaled to the frequencies
in that band.
Allows setting different functionality (compression, Expansion, EQ) per
each band.
For example, its possible to compress the low frequencies with longer attack
release values, at the same time expand the mid range with shorter ones,
DeEss hi-mids with much faster attack and release and boost the super hi
frequencies without any dynamics.
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MultiBand devices are especially handy when dealing with the dynamics of a
full range mix. In a symphonic orchestra as well as in a Rock n Roll band
different instruments dominate different frequency ranges. Many times the low
range dominates the whole dynamic response while the higher frequencies
are riding on top. While it is the mixer’s or composer’s job to reach a desired
balance, mastering engineers often find they need to do something about the
dynamics of the mixed source. It may be to complement it further or indeed
improve its quality, or possibly just make it as loud as possible for competitive
level, with as little degradation as possible.
LINEAR PHASE XOVERS
When the LinMB is active but is idle, it presents only a fixed amount of delay.
The output is 24bit clean and true to the source.
When we use Xovers to split a signal we like to think that they are splitting the
input signal to bands leaving everything else untouched. The truth is that any
normal analog or digital Xover introduces different amount of phase shift or
delay to different frequencies. Further dynamic gain changes will cause
further modulation of the Phase shift introduced by the Xovers. This
phenomenon was treated in C4’s phase compensated Xovers but the initial
phase shift caused by the Xovers is still apparent in C4 and in its output all
frequencies are equal to the source in Amplitude but not in Phase.
When its important to achieve as much source integrity as possible the LinMB
goes a long way and splits the signal to 5 bands maintaining a 24bit clean
starting point for applying different dynamics processing to each of the bands.
Transients are the main sonic events that benefit from Linear Phase.
Transients contain a wide range of frequencies, and are highly “Localized” in
time. A non-linear phase filter that shifts the phase differently for different
frequencies will “smear” the transient over a longer period of time. The Linear
Phase EQ will pass transients maintaining their full sharpness.
ADAPTIVE THRESHOLDS AND DE-MASKING
When a soft sound and a loud sound happen at the same time, the loud
sound has some Masking effect over the softer sound. The research of
Masking, articulated the Upward spread Masking, where loud low frequency
sounds mask higher frequency sounds. The Linear MultiBand provides a way
for each band to be sensitive to the energy in its “Masker” band. When the
energy in the Masker band is high the band’s threshold will rise to introduce
less attenuation and compensate for the masking, letting the sound in each
band come out as loud and as clear as possible. The Linear MultiBand is the
first processor to introduce this de-masking behavior, of which you can read
more in Chapter 3 of this guide.
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Chapter 2 – Basic Operation.
THE WAVES LINEAR PHASE MULTIBANDS CONTROL GROUPS
THE CROSSOVER FREQUENCIES -
The 4 Xover frequencies are set directly under the graph by grabbing their
graph marker or using the text button. These define the cutoff frequencies in
which the WideBand signal will be split into the 5 discrete bands.
INDIVIDUAL BAND CONTROLS -
Each band of Waves LINMB has 5 adjustable dynamics settings.
Threshold, Gain, Range, Attack, Release, Solo and Bypass. These
function similarly in most dynamics processors but in this processor they
affect the dynamics of one of the 5 bands. The Range may seem unfamiliar
and basically it is in place of the well-known Ratio, but it defines both the
intensity of gain adjustment and the limit of gain adjustment. Read more In the
next chapter.
GLOBAL SETTINGS CONTROLS -
In the Global section you can find master controls, which are ganged controls
for moving all the per band controls at once.
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Other deal with the overall processor outputGain, Trim and Dither.
The Makeup control allows selection between manual mode and Auto
Makeup.
Finally there are 4 general compression behavior controls – Adaptive
(Explained further in the next chapter), Release – Select between Waves
ARC – Auto Release Control to a manually set release. Behavior – Opto or
Electro modes affect the nature of the release. Knee - soft or hard knee or
any value in between.
QUICKSTART
To start off, Waves provide a selection of factory presets. These can mostly
serve as good starting points for applying MultiBand Dynamics. As this is not
an effects processor the actual settings have to be program dependant and
most mastering engineers would prefer to manually set the processor and not
rely on ready made settings. The processor defaults and presets offer nice
scaling of the Time Constants Attack, Release in relation to their Band’s
Wavelength providing slower settings to lower bands and faster values to
higher. Other controls are set in the presets to provide some showcase of
possible modes and different combinations.
Start off using the Processor defaults.
Play Music through.
For general MultiBand Compression first set the Range in all bands to –
6dB by dragging the Master Range control downwards. This will assure
that the gain adjustment will be Attenuation or Compression and the
maximal attenuation will not exceed a 6dB reduction.
Now set your nominal per band thresholds. Use the peak energy in each
band to set the nominal threshold to the peak value.
Now you can drag down the master Threshold to set the general
compression. You can choose to engage Auto Makeup after setting the
nominal thresholds and this way further threshold manipulation will
preserve relative loudness and you will hear the compression rather the
change in loudness.
Adjust the per band gains to satisfy or qualify with your idea of “flat”
Equalization.
Play the whole program, or at least the loudest passages and hit the Trim
button to makeup the global output gain buy the its Margin to the full scale.
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Note that this Quick Start routine is not the Golden recipe to mastering with
the Linear MultiBand, it does however provide a general type practice that
should let users new to MultiBand follow a recommended workflow. This
example only scratches the surface of possibilities with the Linear MultiBand
and there are more optional advanced features that may have implications on
the workflow method. Read on in this guide to learn about some of the special
advanced features.
Generally it’s important to remember that while the process is applied to split
discrete frequency bands, it affects the Whole WideBand sound. Soloing each
band and applying its compression in solo and then listening to the whole may
prove unrewarding as a workflow.
Frequency Analyzers can be used to get visual feedback to validate or
articulate what you hear but its most important to use the ears and work in a
good listening environment for critical reference.
Practice Makes Perfect!
This tool presents a lot of choice. Its not the Renaissance tools that help you
save time for great results. It’s a highly flexible, ultra professional, purist
quality tool.
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Chapter 3 – Specialties of the Chef
ADAPTIVE THRESHOLDS AND DE-MASKING.
The effect of louder sounds on softer sounds has been researched for
decades. There are many classifications to masking and the most effective
masking is considered forward in time and upward in frequency. Simply put
loud lower frequencies affect the way we perceive higher softer frequencies.
The loud low frequency mask the higher frequencies. In the LinMB we can
consider each band to be the masker for the band above it, so when the
sound in a certain band is very loud it will have some masking effect to the
sound in the band above it. To address this we can introduce a little lift to the
threshold of the masked band and as result it will get less attenuation and be
a little louder or de-masked.
The Linear Phase MultiBand processor lets each band be sensitive to the
energy in the band below it. The “Adaptive” control is a continuous scale of
sensitivity to the Masker scaled in dB’s. –inf. Adaptive = off, this means no
sensitivity and the threshold is absolute regardless of what’s happening in the
lower band. When increasing the value the band will become more and more
sensitive to the energy in the band below it, The energy ranges from –80dB tp
+12. We call 0.0dB Fully Adaptive and values above it are Hyper Adaptive.
When the energy in the Masker band is high the threshold will be lifted. When
the energy in the lower band falls, the detail is revealed, threshold goes back
down and the attenuation goes back to normal. Also there is a chain reaction
that makes for subtle general looseness of compression to the higher bands
whenever the low bands are with high energy.
Each band of the linear MultiBand has its own compression settings and the
engineer may want to compress more when a band is exposed and less when
its masked. In example a song starts with a solo vocal and then the Playback
comes in and the picture changes. The “presence” frequencies of the voice
become more significant then the lower “Warm” tones of the voice, so to
regain warmth we would want to attenuate it less when the playback kicks in.
This is a macro example that can easily be treated with a bit of automation but
in concept masking happens on the micro scale throughout the program. For
example a staccato bass line masks and exposes the higher band’s sound on
a scale where manual riding isn’t practical. The adaptive behavior is the
practical answer.
The Adaptive De-Masking behavior is new to almost all users, and some may
think it’s unnecessary. It is however interesting, effective and worth a try.
Others may find it useful but it may also call for some practice before you get
comfortable with it. Optionally, it may change they way you work.
As a first step, try to add adaptive behavior to ready made settings on material
that you know very well. Set the Adaptive control to –0dB at this setting you
will get very adaptive behavior. Do a bit of an A > B listening test. Try to pay
special attention to passages that have different spectral dynamic nature and
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hear how the adaptive behavior responds to them adding a more dynamic
approach to dynamics. This example is somewhat extreme and it is
recommended to try settings around –12 dB for subtle adaptive de-masking. It
may also be interesting to lower the overall threshold of the top 4 “Adaptive”
bands by Multi-selecting their thresholds and pulling them down to
compensate for the added looseness, In any case when they are exposed
they will be tighter and Looser when masked.
AUTO MAKEUP
When Applying compression adjusting the threshold reduces loudness.
Indeed in most compressors we can hear the overall gain reduction and we
can apply makeup gain to regain the lost loudness.
In WideBand compressors we find auto makeup to be fairly straightforward.
The auto makeup will boost by the reverse value of the Threshold, or
sometimes have a threshold dependant makeup “range” that accounts for the
knee and ratio too. In MultiBand there are other considerations. The bands
energy is going to be summed with that of the other bands so it’s hard to
predict the part of the discrete band’s energy on the summed WideBand
signal.
The Auto Makeup in LinMB is somewhat similar in that it accounts for the
Threshold, Range and Knee. In wide band we would use the headroom to
boost the loudness further then was possible before compressing. In the
MultiBand case It is designed to help maintain general level stability for better
a/b comparing. While in a wideband compressor the overall level will be
reduced in the LinMB only the gain of a certain band will be reduced in
relation to the others. It is much easier to hear the lost loudness then the
actual compression so working with Auto Makeup the bands level remains
similar and you can focus better on the sound of the dynamics process for
that band. You can choose to use Auto Makeup as a work mode to help get
the per band compression to sound right, Then apply per band gain on top of
it. When disengaging Auto Makeup its effect will be updated into the per band
gains. It is recommended to first set nominal thresholds per band to the peak
energy in each band. Then engage auto makeup and continue to adjust the
desired dynamics.
Auto Makeup does not interfere with the per-band Gain control. Also it cannot
be clipping proofed and the overall Output gain will serve to trim the margin
between the peak and the full scale.
WAVES ARC
- AUTO RELEASE CONTROL
Waves ARC was designed and debuted in the Waves Renaissance
Compressor. This routine sets the optimal gain adjustment release time by
being program sensitive. The Auto Release Control still refers to its band’s
release time and optimizes it according to the actual attenuation assuring
maximal transparency. Before ARC there was always a need to trade
between grainy Distortion with short release times to Pumping when setting
longer release times. ARC helps lower the extent of these artifacts. For best
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results, you may set your release time for the best compromise between
Distorting and Pumping and then apply ARC to get even better results with
less artifacts. Alternatively you can just count on this technology, set your
release value to the desired ballpark or stick with the release scaling from a
preset and rely on ARC to get it right. ARC was so well accepted wherever we
introduced it and in the LinMB it is ON by default.
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Chapter 4 – LinMB Controls and Displays.
CONTROLS
Individual Band Controls
THRESHOLD.
0- -80dB. Default – 0.0dB
Defines the point of reference for that band’s energy. Whenever the energy in
a certain band exceeds the threshold gain adjustment will be applied. For your
convenience, each band has an energy meter for visual adjustment of the
Threshold
GAIN.
+/- 18dB. Default 0.0dB
Sets the overall output gain of the band or the bands makeup value. This Gain
control can be use to adjust the gain of the band even without any dynamics
like an EQ. It is also used to adjust gain of the band that’s being compressed
or expanded to make up for the headroom created buy the compressors
attenuation, or make down to prevent clipping.
RANGE.
–24.0dB – 18dB. Default –6dB
Sets the possible range of the dynamic gain adjustment and also its intensity,
replacing the classic “Ratio” control and adding a firm boundary to it. Negative
Range means that when the energy exceeds the threshold a gain reduction
will be applied, while positive Range means boosting it further. Read more
about range in the next chapter.
ATTACK.
0.50 – 500ms. Defaults scaled for each band.
Defines the time it will take to apply the gain reduction from the moment the
detected energy exceeds the threshold.
RELEASE.
5 – 5000ms. Defaults scaled for each band.
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Defines the time it will take to release the applied gain adjustment from the
moment the detected energy falls below the threshold.
SOLO.
Solo’s the band to the main processors output for monitoring the band-pass
by itself or along with other soloed bands.
BYPASS.
Bypasses all processing on the band and sends it to the main output the
same way it was input. This allows to monitor the processed output vs. the
source for each band by itself.
Crossovers – Xover
There are 4 Crossovers in the liner multiband. Each sets the cutoff frequency
for the High Pass and Low Pass filters that cross each other.
For the calculation intensive nature of the Finite Impulse Response filters the
Xover controls will sound a click when they are reset to a new position. When
using the mouse to adjust the frequency or when grabbing the markers at the
bottom of the Graph, the new filter will be set only when the mouse is
released to avoid zipper noise. Using the arrow keys or control surface you
can advance step by step to fine tune your Xover position. Smooth sweeps
are impossible but the focus should be to set the Xover positions to the
desired cutoff frequency.
Each of the four Crossovers has a unique range of frequencies as follows:
LOW: 40Hz – 350Hz. Default – 92Hz.
LOW MID: 150Hz – 3kHz. Default – 545Hz.
HI MID: 1024Hz 4750kHz. Default – 4000Hz.
HI: 4kHz – 16kHz. Default – 11071Hz.
Output Section
GAIN
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Sets the overall output gain. The double precision process assures no input or
internal clipping so this gain is used at the output to prevent clipping.
TRIM
The Auto Trim button updates the peak value and when clicked it adjusts the
output gain control to trim the margin so that the peak will equal the full digital
scale. For precise clip prevention let the program or at least its high gain parts
pass through. When clipping occurs the clip light will light up and the Trim
control box will update the peak value. Now click the Trim button to lower the
gain by the peak value.
DITHER
The double precision 48bit process can handle overflows. The result however
comes out at 24bit back to the host application’s audio buss. Some native
Hosts may output 32 Floating point output to the mixer or to the next plug-in,
this is the only case where we would recommend not to use the dither. The
Dither control adds dithering back to the 24th bit rather then just rounding
which will be the case when the Dither is off. The dither’s noise and suspected
quantization noise when with no dither, will be very low. The dither however
can let your 24bit result virtually have a perceived 27bit resolution. Any
introduced noise will be further boosted by Limiting the output (With L2 off
course) so we did not want to commit the users to the dither noise and allow it
to be turned off.
In any case, the noise may prove to be well beneath the program’s floor and
audible only at extreme monitoring levels, tucked within the noise floor of the
reinforcement system. Normalizing dithered silence may boost the dither to
terrible noise that is completely out of context. When analyzing non dithered
silence it should remain quite silent, but this does not mean this mode is
superior. The Dither is on by default and its use is recommended unless you
know your host passes 32bit audio back to the host.
Global Behavior Settings
These settings will apply global dynamics process behavior which will
influence the per band compression properties.
ADAPTIVE:
-inf.=Off – +12dB. Default – off.
The Adaptive control sets the sensitivity of a band to the energy in its Masker-
the band below. The control uses a dB scale. The behavior will be that when
there is high energy in a certain band the threshold will be lifted for the band
above it to de-mask it. Read more about Adaptive Thresholds and de masking
in chapter 3.
RELEASE:
ARC or Manual. Default – ARC.
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The Auto release control sets an optimal release time in relation to the manual
release time. When Manual release is selected then the release of the
attenuation will be absolute as indicated, Adding ARC will make the release
sensitive to the amount of attenuation and set the best release time to get
more transparent results.
BEHAVIOR:
Opto or Electro. Default – Electro.
Opto is a classic modeling of opto-coupled compressors which used light
sensitive resistors to control the amount of compression (in the detector
circuit). They have a characteristic release behavior of “putting on the brakes”
as the gain reduction approaches zero. In other words, the closer the meter
comes back to zero, the slower it moves. (This is once the gain reduction is
3dB or less). Above 3dB of gain reduction, the Opto mode actually has faster
release times. In summary, Opto mode has fast release times at high gain
reduction, slow release times as it approaches zero GR. This can be very
beneficial for deeper compression applications.
Electro is a compressor behavior invention by Waves, in that it is very much
the inverse of the Opto mode. As
the meter comes back to zero, the faster it moves. (This is once the gain
reduction is 3dB or less). Above 3dB
of gain reduction, the Electro mode actually has slower release times, much
like a mini-leveler, which minimizes distortion and optimizes level. In
summary, Electro mode has slow release times at high gain reduction, and
progressively faster release as it approaches zero GR. This has very good
benefits for moderate compression applications where maximum RMS
(average) level and density is desired.
KNEE:
Soft =0 – Hard=100. Default - 50
This Master control affects all 4 bands’ knee characteristics, ranging from
softer (low values) to harder (higher values). At the maximum value, the
Master Knee control tends to give the sound a harder edge, with a punchier
overshoot-style character. Adjust to taste. The Knee and Range together
interact to give the equivalent of a ratio control. To achieve limiter-type
behavior, use high Knee settings.
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DISPLAYS
THE MULTIBAND GRAPH:
The MultiBand graph is like an EQ graph showing Amplitude in the Y-axis and
Frequency in X-axis. In the Middle of the graph resides the DynamicLine
that shows the per band gain adjustment as it happens within the Range,
represented by the Bluish highlight. Beneath the graph there are the 4
Crossover frequency markers and on the graph there are 5 markers that allow
you to set the gain of the band by dragging up and or down and the band’s
width by dragging sideways.
THE OUTPUT METERS:
The Output meters show the master output of the processor. Under each
meter there is a peak hold indicator. The Trim control under the meters shows
the current margin between the peak and the full scale. The holds and the
Trim value are reset when clicking in the meters area.
BAND THRESHOLD METERS:
Each Band has its own meter showing the input energy in that band. Under
the meter is a peak hold numeric indicator. When you want to set your
nominal thresholds you can use the peak as reference and then continue to
set them with the master threshold control.
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Chapter 5 – Range and Threshold Concept
The concept of ‘Threshold’ and ‘Range’ instead of the traditional ‘Ratio’
control creates some very flexible and powerful uses for the LINMB. They
include low-level compression and expansion, giving you multiband “upward
compressors” and noise reducers.
OLD SCHOOL / ANOTHER SCHOOL
In the classic compressor approach, if you set a very low Threshold with any
given Ratio, extreme amounts of gain reduction of high level signals may
occur. For example, with a Ratio of 3:1 and Threshold of –60dB will result in a
–40dB gain reduction for 0dBFS signals. Such a case is rarely desirable, and
in general you would only set such a low Threshold in a typical compressor
when the input level is also very low. In common practice, more than -18dB of
gain reduction or +12dB gain increase is rarely needed, especially in a
multiband compressor.
In the LINMB, the concept of ‘Range’ and ‘Threshold’ comes in very handy. It
lets you first define the maximum amount of dynamic gain change using the
‘Range’ control, and then determine the level around which you want this gain
change to take place using the ‘Threshold’. The actual values of these
controls depend on the type of processing that you want.
If Range is negative; you’ll have downward gain change.
If Range is positive; you’ll have upward gain change.
The real flexible fun happens when you offset this dynamic Range with a fixed
Gain value.
HIGH-LEVEL COMPRESSION
High-level compression in C1. Ratio is 1.5:1, Threshold is -35. Equivalent
LINMB setting would have Range set to about -9dB, with Gain set to 0.
If you are interested in conventional compression (termed here ‘high-level
compression’ because the dynamics of the compression happens at high
levels), simply set the Threshold to high values, between –24dB and 0dB, and
the Range to a moderate negative value, between –3 and –9. In this way the
gain changes will take place at the upper part of input dynamics — just like a
normal compressor will do.
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HIGH-LEVEL EXPANSION (UPWARD EXPANDER)
An upward expander from the C1, with a ratio of 0.75:1, Threshold at -35.
Equivalent LINMB setting would be a Range of +10 or so, quite a bit more
than you’d probably ever need. Shown only for clear example.
To make an upward expander (an “uncompressor”) to restore overly quashed
dynamics, simply reverse the Range setting. Make the Range be a positive
value, say between +2 and +5. Now whenever the signal is around or above
the Threshold, the output will be expanded upwards, with a maximum gain
increase of the value of Range. In other words, if Range is +3, then the
maximum expansion will be 3dB increase.
LOW-LEVEL COMPRESSION
The low-level processors are where we start to have even more fun. By using
the fixed Gain control to offset the Range, you can affect only the lower-level
signals.
If you are interested in increasing the level of soft passages, but leaving the
louder passages untouched, (termed here low-level compression’), set the
threshold to a low level (say –40 to –60dB). Set Range to a small negative
value, such as -5dB, and set Gain to the opposite value (+5dB). The audio
around and below the Threshold value will be “compressed upward” a
maximum of 5dB, and the higher audio levels will be untouched, including
their transients.
This will cause high levels signals (i.e. that are significantly above Threshold)
to have no gain Change – since at high levels the Range and Gain controls
are opposite values and together they equal unity gain. While around and
below the Threshold, the Range is increasingly “inactive” and therefore
approaches a zero-gain value. Gain is a fixed value, so the result is that the
low level signal is increased by the Gain control, achieving the so-called
“upward compression” concept.
This is very clear when you see this behavior on the LINMB display. Simply
look at the yellow DynamicLine while the input signal is low or high, and see
the resulting EQ curve. In a multiband compressor application, this low-level
compression is very handy to create a dynamic ‘Loudness Control’ that could
boost the LOW and HIGH bands only when their levels are low, as just one
example.
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Upper line shows Low-level compression (upward), achieved when Range is
negative and Gain is equal but positive. Lower line shows Low-level
expansion (downward), achieved when Range is positive and Gain is equal
but negative. Graph is taken from C1 to help visualize the gain structures in
the LinMB.
LOW-LEVEL EXPANSION (NOISE GATE)
If you are interested in a noise gate for a particular band or bands, set Range
to a positive Value, Gain to the inverse of the Range, and Threshold to a low
value (say -60dB). Similar to the above example, at high levels the full
dynamic gain increase set by the Range is retained, and is fully compensated
for by the Gain. While around and below the Threshold, the dynamically
changing gain comes closer to 0dB, and the result is that the fixed negative
Gain is applied to the low level signal — which is also known as gating (or
downward expansion).
“UPSIDE DOWNTHINKING
These low-level examples may seem a little inverted to what you would
expect. For instance, that a noise gate would have a positive Range.
If you just remember that when the signal goes around the Threshold, then
the Range becomes “active”, and that the Threshold is the halfway point of
the Range. So whether Range is +12dB or –12dB, then audio 6dB above and
6dB below the Threshold is where the “knees” of the dynamic change will
occur.
Positive Range
Then, if Range is positive and Gain is set to be the negative of Range
(opposite but equal), then around and above the Threshold all audio will be a
0dB gain (unity). Below the Threshold, the Range is not active, so the Gain
(which is negative) “takes over” and reduces that band’s gain. This is what
gives the downward expansion.
Negative Range
Another seeming example of the “upside down” concept is that low-level
compression takes a negative Range. Again, remember that in the LINMB,
whenever the audio is around the Threshold, the Range is active. So, if we set
Range to negative, anything around or above the Threshold can be reduced
in gain. However! Here’s the tricky part: if we set Gain to perfectly offset the
Range value, then everything well above the Threshold has no effective gain
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change at all, which means everything well below it gets “lifted up”. (If you
take this just a bit further, you’ll figure that all audio exactly at the Threshold
will have half of the Range’s value in positive gain).
ONE MORE WAY TO THINK ABOUT IT
Here is another bit of help so that you can really learn and use the power of
the LinMB to its fullest capability. We’ll take another example from the Waves
C1 Parametric Compander, our one-band processor (it also does wideband
and sidechain). It has a typical ratio and makeup gain control and has been
widely used for upward compression (both wideband and split-band
parametric usage).
The Linear MultiBand Parametric Processor has a very similar compressor
law as the Waves C1 and the Waves Renaissance Compressor. This model
allows the “compression line” to return to a 1:1 ratio line as the level continues
to increase. In other words, there is no compression of the low signal,
compression around the Threshold, and once the signal goes quite a bit past
the Threshold, the compression tapers off back to a 1:1 line (no compression).
In the graphic shown, you can see this exact type of line. The ratio is 2:1 and
the Threshold is –40dB. The line is just curving a bit (-3dB down point) at the
–40 input (the scale at the bottom). Output level is the scale on the right
vertical edge, and you can see that at about –20dB, the line starts curving
back to a 1:1 line.
So, very high-level audio peaks between 0 and –10dBFS are not touched at
all, audio between –10 and –40 is compressed, and audio below –40 is not
compressed, but is clearly louder at the output than at the input. This is low-
level compression, or “upward compression”. Such a trick is very useful and
has been implemented by classical recording engineers, mastering houses,
and classical broadcasting. Low-level compression can “lift” soft sounds up
gently and leave all the high-level peaks and transients completely untouched,
reducing the dynamic range from the bottom upwards.
We did say that the LinMB was “very similar” to the C1, but different in a
significant way: the Threshold defines the midpoint of the Range. Therefore,
to achieve the same curve in the LinMB as shown here, the Threshold on the
LinMB would actually be about –25 with a Range setting of +15.5dB. Now this
is a very large amount! The example shown here was merely to make it
obvious; we picked the 2:1 line only because it is easier to see on the page. In
reality, low-level compression that lifts the softer audio up 5dB is equivalent to
an approximate ratio of 1.24:1. Lifting the low-level up about 5dB is a good
Waves LinMB software guide page 19 of 28
example for several reasons. It is (1) a very realistic setting that could be
equal to what is being done by the previously mentioned engineers; (2) only
raising the noise floor by an acceptable amount for many applications; (3)
easy to hear on nearly any type of audio, not only classical. In the Load menu
of the LinMB are a few factory presets with names beginning “Upward
Comp…” that are good points to learn more about this concept. More presets
are in the LinMB Setup Library.
In the next chapter there are more specific examples of using low-level
processing (compression, expansion) that are very good starting points as
well as models for learning.
Waves LinMB software guide page 20 of 28
Chapter 6 – Examples of use
PRACTICE OF MULTIBAND AND MASTERING
Upon a time the mediums just couldn’t handle the same dynamic range that
an orchestra can produce or a Microphone transduce, so for the lower
passages not to be too low and the peaks not too high, compression and peak
limiting was used. In broadcasting AM signals, the hotter the signal was the
further it would reach. Since heavy wide-band compression causes
modulation distortions these industries used EQ Xover filters to split the signal
and feed it into separate compressors and then mix back. Today’s mediums
for both transmission and local music playback have a dynamic range that is
quite fit to carry extreme dynamics, yet compressors are still heavily used in
most cases and in some to an extreme extent.
We find that nowadays the Mastering stage is where broadband signals are
processed with compression for best translation from the low noise
professionally equipped mixing environment to the hi fi home systems,
personal headphone players or car reproduction systems. At this stage it is an
art of subtlety to complement a ready-made mix while effectively taking
advantage of the target media properties and the typical target reproduction
properties to reach a certain optimum.
The master will be the carrier of the so-called “Flat” response of the program
material. This “Flat” response may well be further processed at the listener’s
side for boosting or cutting frequency ranges according to taste driven
preferences. While we can reach relative flatness with EQ devices, it may
sometimes be complementary and perhaps necessary to add some frequency
range dependant push or pull to fit even better. It’s like putting the mix on
vitamins, making it as potent as possible in all frequency ranges to cut
through best at any given playback scenario.
It is recommended to apply MultiBand dynamics as a first generation of
mastering compression before applying another stage of wide band limiting.
This way more transparency will be maintained for a similar amount of
loudness gained. The MultiBand stage will serve to optimize the dynamics of
the broadband signal for that final stage. As indicated before it is a subtle
trade. The taste and experience of the mastering engineer will determine the
result and the Linear MultiBand may serve as a purist level tool offering total
transparency when splitting the signal to 5 discrete bands for the engineer to
do he’s thing.
That aside, we recommend trying the Multiband Opto Mastering
preset, or the Basic multi preset. Either one will give you reasonable
compression and increased density of your mix.
To enhance low-level signals (a great way to boost level without squashing
dynamics), try the Upward Comp +5, or +3 version of the preset. This is
great for adding level without losing punch.
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Waves LinMB Linear Phase MultiBand Software Audio Processor User guide

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User guide

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